[openib-general] openMPI for 2.6.17.10 kernel

[Steve Wise]

> This is not what I understood from conversations in Tampa last week.
> 
> OMPI does not use CM at all today (RDMA CM or plain CM).  Instead,  
> OMPI *only* uses its out-of-band connection to exchange information  
> to then create queue pairs manually.  Leaving out all the details, it  
> does something like this:
> 
> 	// initiatior
> 	ibv_create_qp(...);
> 	ibv_modify_qp(...);// set pkey, port num, etc.
> 	send_via_oob_channel(lid, mtu, my_port_num, ...other info...);
> 	wait_for_oob_reply(...);
> 	ibv_modify_qp(...);//set mtu, lid, remote_port #, etc.
> 
> Are you telling me that the *ONLY* way to make QPs over iWARP  
> connections is to use the RDMA CM, and it is not possible to work  
> using a scheme like i listed above (passing relevant info via OOB  
> channels)?  

Yup.  

> If so, I'm curious: what magic is the RDMA CM doing such  
> that this is necessary?
> 

Setting up an TCP connection and negotiating RDMA mode.